This application claims the priority of Korean Patent Application No. 10-2005-0011593, filed on Feb. 11, 2005, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a probe for a data storage apparatus, and, more particularly, to a probe for a data storage apparatus having high resolving ability and excellent durability.
2. Description of the Related Art
As compact products, such as mobile communication terminals and electronic pocket notepads, become more popular, the demand for a micro integrated non-volatile recording medium increases. However, it is not easy to downsize conventional hard disks nor to highly integrate flash memories. Therefore, a data storage apparatus using a scanning probe has been studied as an alternative.
Probes are used in various scanning probe microscopy (SPM) techniques. For example, probes are used for a scanning tunneling microscope (STM) which detect a current produced when a voltage is applied between a probe and a sample to reproduce information, an atomic force microscope (AFM) which uses an atomic force between a probe and a sample, a magnetic force microscope (MFM) which uses an interaction force between a magnetic field from a sample and a magnetized probe, a scanning near-field optical microscope (SNOM) which overcomes a resolution limitation due to the wavelength of visible light, and an electrostatic force microscope (EFM) which uses an electrostatic force between a sample and a probe.
In order to record and reproduce high density information at high speed using such SPM techniques, a nanometer probe is required. Thus, a sharp-type probe may be used, but the sharp-type probe is readily abraded compared to a blunt-type probe.
FIGS. 1 and 2 respectively illustrate pictures of a conventional sharp-type probe and a conventional blunt-type probe obtained during experimental tests for recording and reproducing information. FIGS. 3 and 4 respectively illustrate numerical results of the tip abrasion degree and areal density for each of the probes of experimental results of FIGS. 1 and 2.
Referring to FIGS. 1 through 4, when the same amount of load is applied to the sharp-type probe and the blunt-type probe, the degree of abrasion of tips of each of the probes can be observed. In this experiment, the radius of the tip of the sharp-type tip is 5 nm, the radius of the tip of the blunt-type probe is 50 nm, and the load applied to each of the probes is 30 nN, and the movement speed of each probe is 2 μm/s.
According to the results of the experiment, when the same load is applied to the probes, the tip of the sharp-type probe is abraded more seriously than the tip of the blunt-type probe. This is because the radius of the sharp-type probe is smaller than the radius of the blunt-type probe, and thus, an area to which the load is applied is reduced. Consequently, more pressure is applied to the tip of the sharp-type probe even if the same load is applied to the sharp-type and blunt-type probes.
Since the sharp-type probe has better resolving ability than the blunt-type probe, the sharp-type probe is preferred over the blunt-type probe in manufacturing a high density recording apparatus. However, the degree of abrasion of the sharp-type probe is higher than that of the blunt-type probe.